Field
Exemplary embodiments relate to an apparatus and method for measuring motor speed, and more particularly, to an apparatus and method for measuring motor speed using a low-resolution encoder.
Discussion of the Background
In general, the speed of a motor is measured through a rotary encoder. The rotary encoder includes an absolute encoder which outputs the absolute position of a shaft and an incremental encoder which outputs information on a motion of a shaft.
When such an encoder is used to measure the speed of a motor, the accuracy of the measurement is generally determined by the resolution of the encoder, which is defined by PPR (Pulse Per Revolution). That is, when a high-resolution encoder is used, the accuracy of the measured motor speed may be increased more than when a low-resolution encoder is used.
However, since the high-resolution encoder is more expensive than the low-resolution encoder, the high-resolution encoder is disadvantageous in terms of cost.
The related art of the present invention is disclosed in Korean Patent Laid-open Publication No. 10-2004-0017954 published on Mar. 2, 2004.